1. Field of the Invention
The present invention relates to a radiation-sensitive resin composition.
2. Discussion of the Background
In the field of microfabrication represented by fabrication of integrated circuit devices, a photolithographic technology enabling microfabrication with a line width of about 100 nm or less using an ArF excimer laser (wavelength: 193 nm) or the like has been demanded in order to achieve a higher degree of integration. As a radiation-sensitive composition applicable to excimer laser radiation, a number of chemically-amplified radiation-sensitive compositions utilizing a chemical amplification effect between a component having an acid-dissociable functional group and an acid generator which is a component generating an acid upon irradiation, have been proposed. For example, a photoresist polymer compound containing a resin component with a specific structure which contains a monomer unit having a norbornane ring derivative as a resin component has been known (for example, JP-A-2002-201232 and JP-A-2002-145955). A resist composition using (meth)acrylic acid copolymer with a narrow molecular weight distribution which contains an ester of a (meth)acrylic acid with a specific monocyclohexane carbolactone, bicycloheptane carbolactone, or the like as a repeating unit has also been known (for example, JP-A-2003-84436). Moreover, a radiation-sensitive resin composition containing an acrylic polymer which contains a repeating unit having a lactone ring, a repeating unit having a polyalicyclic hydrocarbon group consisting only of carbon and hydrogen and not containing a polar group, and a repeating unit having an acid-dissociable group has been known to reduce pattern line edge roughness after development and heat treatment dependence after irradiation when used as a chemically-amplified resist responding to deep ultraviolet rays represented by an ArF excimer laser (wavelength: 193 nm) (for example, JP-A-2005-68418).
However, in order to achieve a higher degree of integration of semiconductor devices, a radiation-sensitive resin composition used as a resist has been required to possess more excellent resolution. In addition, along with the progress of miniaturization, low focus latitude and pattern form degradation have become serious problems. In order to deal with these problems, urgent development of a radiation-sensitive resin composition excelling in resolution, having a wide focus latitude, and producing an excellent pattern shape has been desired.